The present invention relates in general to sign constructions, and in particular to a new and useful single or multiple face sign which utilizes flexible sign face material.
A wide variety of tensioning system for flexible sign face is known. See for example U.S. Pat. No. 3,885,335 to Egermayer which shows a double face sign having flexible face material and edge systems for tensioning the material. A back lighted sign using flexible material is also disclosed in U.S. Pat. No. 4,185,408 to Tracy. A sign having a flexible sheet material stretched on a heavy duty frame which is hinged to a sign box is disclosed in U.S. Pat. No. 4,516,343 to Stilling.
Flexible double face signs on the order of eight feet square and smaller are not economically feasible when compared to double face rigid acrylic signs common in the industry today.
Flexible double face signs with lighted graphics or displays on opposite sides require a stronger frame than rigid acrylic double face signs. Tensioning of the flexible vinyl creates a stress load of 30 lbs per square foot (pfs) that must be resisted by the frame. The flexible vinyl also transmits wind loads to the frame in a different manner than rigid acrylic, again requiring additional frame strength. Adding strength to the frame creates an exponential increase in cost and weight. The cost vs. strength equation has created an economic barrier in the sign industry which no one has been able to overcome.
In addition, one or both sign faces in a double face sign must be hinged to open and provide access to the interior of the sign for lamp and ballast maintenance. A rigid frame around the perimeter of the flexible sign face must be strong enough to resist tensioning and wind loads.